Bizarre Overflow Problem!

[jimmyj77]

I know there are probably a million and one people asking about overflow pipes....but....i dont think this has been covered.

Ok. The problem: streaming of water out of the overflow pipe (from upstairs). So one of the tanks in the loft is overflowing.

A plumber has changed the ballcock in the larger (cold) water tank. The smaller hot water tank (which is a bit of a pain to access - daft location) seems fine.

Despite this change of ballcock the overflow problem still persists. And its definitely the cold water tank overflowing as everytime i get back from work i can see water pouring out (of the flow pipe), so i go into the loft and sure enough its from that tank.

I have tried turning the heating off to see if that affects anything. No difference at all.

The water in the tank is clear (apparently it would be dirty if water from the tank in the airing cupboard) was somehow getting in there.

I just dont understand where the water is coming from to fill up the tank?

By the way if this sounds like i dont really have a clue about these things then you'd be spot on!!

Any advice at all??

Thanks,
JJ

 

[LeedsPlumber]

Have you got any mixer taps that may not be shutting off properly, cold water could be going back down hot pipe pushing water in to the tank.

 

[jimmyj77]

Mixer taps? Take it you mean a tap through which both hot and cold go through (sorry - my knowledge is pretty much zero!)? Havent got any taps leaking - is this how i would know?

 

[LeedsPlumber]

Yes a tap that does hot and cold with a lever that you use to bled the hot and cold, http://www.qssupplies.co.uk/bathroom-furniture-shower-taps/429.htm[url] something like that, if the lever is not completely down even though there is no water coming out the cold can still push its way down the hot pipe.[/url]

 

[jimmyj77]

Nope - unfortunately the lever is fine!

Had a plumber round 3 times now and even he can't understand it ("not seen anything like it in 40 years...")

To be honest i think it's something simple that hasnt been thought of yet. Ever the optimist etc etc!

Thanks for reply by the way.

 

[Agile]

Nope - unfortunately the lever is fine!

Had a plumber round 3 times now and even he can't understand it ("not seen anything like it in 40 years...")Thanks for reply by the way.

Obviously you need a competent plumber!

These water based problems are so simple that it surprising that anyone calling themselves a plumber cannot solve it.

Whilst you should pay for the new valve he should not have been paid any more as he changed a part whcih was not necessary to fix the problem. ( It might have been overdue for replacement though ).

It seems that you dont even know which tank is involved.

Can I suggest you look at both tanks yourself and see which one is over flowing and how far the ball float is inside the water when that occurs.

Tony

 

[ddk]

if everything else has been checked (tap valves, ball valves etc) then the only other explanation is the cylinder. if the coil in the cylinder is corroded/split it will pass water from the heating system into the water tank. i would advise you had this checked as you dont want to be washing your dishes or having a bath in water that may have been contaminated with chemicals from your heating system

 

[stardanny]

A plumber has changed the ballcock in the larger (cold) water tank. The smaller hot water tank (which is a bit of a pain to access - daft location) seems fine.

Hi.

Is the smaller hot water tank ( this might be a header tank for heating? ) higher than larger ( cold ) water tank? If it is then the cylinder has a pinhole leak thru coil. Your plumber should be able to check easy.

Dan.

 

[Softus]

I just dont understand where the water is coming from to fill up the tank?

It's coming from the hot water cylinder, in the reverse direction up the cold feed.

It's happening because you have unbalanced supplies feeding a mixer valve, and a missing or faulty check valve.

Ignore Agile's comments - he's not very good at staying focussed on the topic in hand.

 

[AndyPRK]

1) Have you got any tanks higher than the one which is overflowing ?

2) Can you see water entering the overflowing tank from the top ?

 

[seco services]

softus has already given the answer to the problem.

 

[jimmyj77]

Many thanks for all your replies - apologies for the delay didnt have access to the net over the weekend.

Just to clarify a couple of things: the smaller tank is lower than the larger tank ruling one possible solution out and the water is definitely coming in from the bottom of the tank - which means that Softus' suggestion sounds like the problem solver.

Question is - how to get this checked out. Is it worth feeding this advice to a different (more competent) plumber? Probably not something i could have a stab at??

cheers again.

 

[Softus]

Question is - how to get this checked out.

Easy.

Wait until the cistern starts overflowing, and shut off the cold main supply to the cistern. The water will continue to overflow at the same rate.

Then shut off the cold main supply to the entire house. The water will stop overflowing.

Do not open any taps during this test, or it will make the results meaningless.

Is it worth feeding this advice to a different (more competent) plumber?

No.

Probably not something i could have a stab at?

I would say that you can easily have a stab. You can add a non-return valve (aka check valve) in the outlet from the cistern, or the outlet from the cylinder (after the vent), or both.

If this fails to work then you need to identify the mixer valve at the source of the trouble. It's usually a shower valve.

As another experiment, turn all shower valves to either full cold or full hot, which should close off the path that the water is taking. This test is not conclusive, but if it works then you have a workaround to use while you're planning the permanent fix.

 

[Agile]

Question is - how to get this checked out.

Easy.

Wait until the cistern starts overflowing, and shut off the cold main supply to the cistern. The water will continue to overflow at the same rate.

Then shut off the cold main supply to the entire house. The water will stop overflowing.

Do not open any taps during this test, or it will make the results meaningless.

My assessment of that "advice" is that instead the small tank will continue to overflow until the big tank is down to the same level because its probably the heating coil being leaked into by the cylinder.

Softus seems to have got a bit mixed up between heating and cold supply tanks! A leaking mixer tap as he suggested would only affect the "big" tank!

Tony

 

[Softus]

My assessment of that "advice"...

Your assessment, you complete ***kwit, is utter garbage, since you've utterly misconstrued which cistern is overflowing.

...its probably the heating coil...

"Probably" just about sums you up.

Until you can start trading in certainties and objectivity, kindly **** off.

Softus seems to have got a bit mixed up between heating and cold supply tanks! A leaking mixer tap as he suggested would only affect the "big" tank!

Incompetent ****er.